Revert to using simple CMAKE_INSTALL_PREFIX

Author: cschreib

CMakeLists.txt

@@ -10,19 +10,19 @@ set_target_properties(oup PROPERTIES EXPORT_NAME oup::oup)
 
 target_sources(oup INTERFACE
     $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include/oup/observable_unique_ptr.hpp>
-    $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}/oup/observable_unique_ptr.hpp>)
+    $<INSTALL_INTERFACE:${CMAKE_INSTALL_PREFIX}/include/oup/observable_unique_ptr.hpp>)
 target_include_directories(oup INTERFACE
     $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
-    $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>)
+    $<INSTALL_INTERFACE:${CMAKE_INSTALL_PREFIX}/include>)
 target_compile_features(oup INTERFACE cxx_std_17)
 
 # Setup install target and exports
 install(FILES ${PROJECT_SOURCE_DIR}/include/oup/observable_unique_ptr.hpp
-    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/oup)
+    DESTINATION ${CMAKE_INSTALL_PREFIX}/include/oup)
 install(TARGETS oup EXPORT oup-targets)
 
 install(EXPORT oup-targets
-  DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/oup COMPONENT Development)
+  DESTINATION ${CMAKE_INSTALL_PREFIX}/lib/cmake/oup COMPONENT Development)
 
 export(EXPORT oup-targets)
 
@@ -31,13 +31,13 @@ include(CMakePackageConfigHelpers)
 configure_package_config_file(
   "${PROJECT_SOURCE_DIR}/cmake/oup-config.cmake.in"
   "${PROJECT_BINARY_DIR}/oup-config.cmake"
-  INSTALL_DESTINATION ${CMAKE_INSTALL_LIBDIR}
+  INSTALL_DESTINATION ${CMAKE_INSTALL_PREFIX}/lib
   NO_CHECK_REQUIRED_COMPONENTS_MACRO
   NO_SET_AND_CHECK_MACRO)
 
 install(FILES
   "${PROJECT_BINARY_DIR}/oup-config.cmake"
-  DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/oup COMPONENT Development)
+  DESTINATION ${CMAKE_INSTALL_PREFIX}/lib/cmake/oup COMPONENT Development)
 
 # Setup tests
 if (OUP_DO_TEST)